8x12 (8x14) Lathe Mods

[TroyO]

I figured I'd start a thread about what mods I've done on my lathe, and how they worked out. Some were details of not much importance, but handy in some way. Some actually change the way the machine works, but most of those are still in progress. I've searched high and low about mods others have done, copied some and figured if I dumped all mine in one place it might make the searching easier. I'm also going to include ratings of approximate costs, difficulty and how much it made use of the lathe better. Lastly I'll list any stuff I want to do at a later date to make stuff even better, and how much I think it will make it better.

If anyone else wants to pile in some 8x14 Mods, have at it! I’m always looking for improvements that make it easier to make something!


1) QCTP... (Quick Change Tool Post) I got the starter kit from Littlemachineshop which included the A2Z CNC QCTP. Install was pretty easy, I had to drive out the stud from the compound slide and cut the boss down a little bit. I am going to revisit this soon-ish... I'm not so sure the mounting system is as good as it could be. I'm looking for a bit more rigidity from the assembly and I think some simple changes could help with that. After an initial fit and finish problem (Loose fit of the dovetails on the holder so it wouldn't lock properly) which A2Z was happy to help with (I live by them so I stopped at the shop.) I got it all up and working.

Cost: About $160, because I got several extra tool holders.
Difficulty: 4 Would have been 3 if not for the fit/finish problems.
Effectiveness: 8 I can't imagine having to shim/readjust bits every time.
Potential improvement: 6
a) Make a new spacer that's square and supports entire base, possibly lower the mounting boss more and use a thinner spacer.
b) Improve the hold down nut... make a steel one on the lathe that fits precisely and will be stronger/stiffer than the AL one.


2) Put a spring on the chuck key so it can’t be left in the chuck. It works… slightly inconvenient but not majorly so, once you get used to it.

Cost: $0.50 (Hardware store random spring)
Difficulty: 0.5
Effectiveness: 6
Potential Improvement: May make a chuck key “Holster” that cuts the power instead.


3) Put a spring on the bolt that locks the tailstock. That way when you loosen it, it doesn’t “stick”.

Cost: $0.50 (Hardware store random spring)
Difficulty: 0.5
Effectiveness: 6


4) Ground/polished gibs. I removed the compound and cross slide and gave them a thorough going over. I used wet/dry sandpaper glued to a granite tile to grind down the gibs until I got a dead flat and polished set of gibs. I re-installed and adjusted then and was definitely able to get a tighter fit, but at the cost of some friction. Again, something else to revisit...I suspect that there aren't enough gib adjustment screws on the machine to get a perfect fit. I think you end up adjusting the gibs tight but it's bowing back out in between adjusters making tight/loose spots. More adjusters would even out the tension and I think you'd get lower friction and tighter fit.

Cost: About 6$ (Portion of spray adhesive, 5 or 6 sheets of wet/dry paper)
Difficulty: 4 (Just because of having to disassemble/reassemble/readjust 2 major components)
Effectiveness: 5 (Good idea, but not vital)
Potential Improvement: 4 (Install more adjustment points)


5) Removed the slip ring, got rid of the spring clip and packed it with Teflon tape instead. I'm not sure what the real term for those dials is, but it's the ones where you can set a zero point. I read elsewhere that someone else had done so and I liked the idea. In hindsight, I wouldn't have bothered. It doesn't feel that different.

Cost: $0.50
Difficulty: 2
Effectiveness: 0
Potential Improvement: None


6) Installed a knob on the belt cover.
I had a little knob that I threaded in to the lathe in place of the phillips head screw so I didn't need a tool to open the belt cover.

Cost: $1 (Just random junk)
Difficulty: 1
Effectiveness: 4 (Got rid of an irritation)


7) Installed allen head bolts on the compound base. I took the studs and drilled out the bases, then tapped them ¼-20 to take allen bolts. The original studs were soft, and had started to strip out.

Cost: $2
Difficulty: 2
Effectiveness: 4 (Got rid of an irritation)


8) Variable speed drive (Yay! A big one!) I raided SWMBO's (She Who Must Be Obeyed) treadmill and yanked out all the juicy bits. One of the juicy bits was a 1.5 HP DC motor, and speed controller. The speed controller tanked because of my own stupidity, otherwise I would have used it as well (Shorted it and let out the magic blue smoke). I think it will actually work out better that I didn’t use the treadmill’s speed control. I suspect, based on the size of the board and heatsinks that it wasn’t able to fully power the motor anyway. It makes sense that treadmill manufacturers would want to fudge the numbers… drop in a 1.5 HP motor, and a .75 HP controller and advertise the fact that it has a 1.5 HP motor… ignoring that it can’t actually run at 1.5 HP. Anyway… got a real 1.5 HP controller, but keep in mind that you could knock $80 off the cost if you have a better controller on your treadmill, and manage not to smoke it by accident. This upgrade isn’t done yet, so my numbers are my best guess. I will update when it’s actually finished.

Cost: $160* (Not including treadmill salvage)
Difficulty: 8*
Effectiveness: 8* (I hope, anyway!)


Hit List of stuff I want to mod/change/improve:
1) DRO350 from Shumatech (Module ready, scales not mounted yet.)
2) Rework QCTP mounting
3) Extra gib adjusters
4) 4 Jaw chuck

I’m sure I’ll come up with some more, LOL. I'll update the thread as I come up with any other Mods... there may be some I forgot about and didn't list.

Anyway... any other 8x12 / 8x14 Modders out there? There's tons for the 7X lathes, but the 8X line is becoming more popular as time goes by... I'm sure someone out there has some good stuff!

[TroyO]

Update: I completed the treadmill motor upgrade. It seems to work awesome!

100 RPM to 1850 RPM so I lost a little top end but am able to slow things down a bit more.

I still have 3 stages of the belt pulley too, so if I really need the top end I can up the gearing a stage and get in excess of 2500 RPM. (or around 3800 if I go to the highest belt.)

I haven't actually turned with it yet, just got the controller tuned up. I had to adjust the Max pot a bit, it was 0nly getting to 78V with the factory trim.

I also bumped IR which seemed to help low end torque... I can barely stall it by hand at 100 RPM.

I'll post more when I get a chance to do some real work on it. I think my next project will be a new tool post hold down nut and spacer for the base... to try and stiffen up the A2Z CNC toolpost some.

[ToddK]

Hi Troy,
I also purchased the A2Z quick change tool post. The best thing I ever did for my HF 8x14 lathe was to toss the A2Z QCTP and replace it with the one from Lathemaster. The lathemaster is enormous compared to the A2Z, and is much more stable, and accomodates larger tools. By way of comparison, the A2Z accomodates a 3/8" boring bar, the lathemaster can take 3/4", which enables me to bore out cansisters for my divelights that are 7" deep. -Todd.

[TroyO]

Ya.... it probably wasn't the best choice. Somehow I ran in to the posts knocking it AFTER I bought it, LOL.

I might have gotten the Lathemaster one anyway, but after sending him 2 emails with no response I gave up.

Anyway... like most things the A2Z could use some tweaking. This is what I did to help with some of it's issues.

It seems to have helped A LOT as far as rigidity. Overall the idea was to improve the fit and finish of the hold down nut, and maybe replace the stud with a bolt of some kind. It ends up, that's not what I did... but this seems to have worked out pretty well.

I threaded the existing stud to 3/8-24. It just happened to be about the right diameter, (.385) so it was an easier fix than replacing it with some other bolt. That way, the clamping force is acting directly on the QCTP instead of from the top of the stud and it's inherent flex. It's also a larger thread than the top of the stud, and there's a couple of inches of the shaft that's threaded instead of about .75 inches. As a bonus... the stud still works for the original parts too.

Then I used a 5/8ths bolt to make a new hold down nut. I cut it to length, faced the end and drilled/tapped it for 3/8ths-24 to match the new threads on the existing stud. The unthreaded shaft portion of the 5/8 bolt was about a perfect fit for the barrel of the A2Z QCTP. It's also steel, instead of AL which should help strength as well.

Another change was I used a 7/8ths steel washer to replace the aluminum one that shipped with the A2Z. It's about 2/3rds as thick so I ended up knocking the stud out to file down the boss just a little bit. It should have less give than the AL one, and it's a bit larger on the OD so it's fully supporting the QTCP so you get a little bit of rigidity there too.

I also machined the head and added a built in lever, but that's not really necessary... you could also leave it a hex head. I wanted the convenience..... I also didn't want the hole to go all the way through so I couldn't just chuck the bolt up with the head pointing at the tailstock and drill through. It would have been easier to just leave the existing hex head and drill it through, but ohh well. I was putzing.. LOL.

[TroyO]

Hmm... couldn't figure how to add pics so here's one that shows what I made a bit better.

[TroyO]

Here's a couple of the treadmill upgrade.... which worked a treat during all this. I could stall it at 50 RPM, but not that easily. Anything over that never showed signs of slowing down.

Pic 1 shows the motor mounting, and the belt setup. It also shows the gobs of extra room in the back that I could have used for the motor controller... hindsight 20/20. The pulley is black/silver because it triggers the tachometer on the Shumatech. So far, that's all the Shumatech does is read RPM, LOL.

Pic 2 shows the control panel and the handy dandy light that I added while I was in there. (I like that a lot.)

Pic 3 shows the AC/Reverse switch interlock that I came up with... which works perfect. It also shows the connections that go to the box, and the white thing at the bottom of the back panel is a regular double AC outlet... one for the motor controller that is switched/interlocked and the other is always on... eventually for the Shumatech DRO.

Pic 4 is the motor controller box, with fan that I made out of an cheap cash box.

[blades]

Nice work, Troy! You GOTTA clean off that bench though!

[TroyO]

Hahaha... true that!

Clean up is today's task.... it's usually a little better than that but I've mostly been working ON the lathe rather than WITH the lathe lately, LOL.

[blades]

LOL, I'm familiar with that concept ... the lathe itself is my hobby right now. Hopefully when things get settled down from our upcoming move I will be able to get back into it.

[TroyO]

Here's a mod to a mod? Re-mod? re-rolled re-mod?

Anyway, found out while turning a chuck backplate that I didn't have quite enough torque to make me happy, so I bolted a Cevy 350 small block to it.... (kidding. ;-)

What I did do was put some of the belt drive components back on, which gave me a set of speed ranges.

I was at about 100-2000 RPM and no way to change it.

Now, my ranges are:
50-1000 RPM (Double the torque... bwahahha!)
90-1600 RPM (Most common usage range)
200-3300 RPM (A 6 inch chuck at 3300 is a little nervous-making. ;-)

And the best part.... I didn't have to make ANYTHING to do it, LOL. I simply flipped over the drive pulley, and bolted the stock secondary pulley back on.

Pic 1 is the old setup.. single range, straight belt.
Pic 2 is the new setup at 50-1000
Pic 3 is 90-1600 RPM
Pic 4 is 220-3300

[madbee]

TroyO, thanks for posting these ideas. I just got an HF 8x and tried out two of your mods. I know this is real simple stuff, but they worked so well, I thought I would post the details. The way the tailstock clamped down really bugged me. Sometimes I would have to make the bolt very loose so that it would move freely (or at all). Anyhow, I picked up a 2-pack bag of springs at Lowes Hardware that worked as if they were custom made for both applications without modification...just the right length and tension. I only had to bend one spring slightly to hook onto the chuck key. I attached a pic of the spring packaging just in case someone wanted to get these same springs. I also needed one 1/2" fender washer. Now I just loosen the tailstock nut a little and it glides along the way.

Also, buying from HF, there was no chip tray included. I came up with a compromise that fit pretty well. It's a simple Carlisle 14x18 food tray from Amazon. It slides out for easy cleaning (lets see your chip tray do that - lol)...and it was only around $10 shipped. I was going to buy black, but then thought grey might reflect light better.

First time posting pics, hope this works.

Originally Posted by TroyO 2) Put a spring on the chuck key so it can’t be left in the chuck. It works… slightly inconvenient but not majorly so, once you get used to it. 3) Put a spring on the bolt that locks the tailstock. That way when you loosen it, it doesn’t “stick”.

[bodysnatcher]

very nice madbee very nice

billz